FIG. 1 shows a structure diagram of a cellular wireless communication system; as shown in FIG. 1, the cellular wireless communication system mainly consists of a Core Network (CN), a Radio Access Network (RAN) and terminals. The CN is responsible for non-access layer affairs such as terminal location update; in addition, the CN is also the anchor point of the user plane. The RAN comprises base stations, or comprises base stations and a base station controller, wherein the access network is in charge of access layer affairs such as management of radio resources; depending on actual situations, there might exist physical or logical connections between base stations, for example, the connections between base station 1 and base station 2, as well as between base station 1 and base station 3 as shown in FIG. 1; in addition, each base station can be connected with one or more CN nodes. The terminal, i.e., the User Equipment (UE), refers to various devices capable of communicating with the cellular wireless communication network, such as a mobile phone or a laptop computer.
A MTC service is a machine to machine communication service. In the MTC service, human participation is not needed and all communications are automatically performed by machines; the MTC service obtains data through sensing devices such as a sensor, then reports the data to a mobile communication network through a communication module and accesses a public data network through the mobile communication network. Specifically, the MTC service can be applied to logistics supervising, security monitoring, remote medical detection, remote meter reading, etc. The data is managed by a special server of a mobile operator or dedicated MTC operator, and can be provided for view by an MTC user or MTC manager. During this process, the device acquiring the data needed by the service is the MTC equipment.
In the MTC service, some features distinct from the conventional mobile communication are introduced, for example, the feature of group management. When this feature is activated, the MTC equipments of the same user may be classified into one group; the network can uniformly configure parameters for the whole group. The parameters apply to all MTC equipments belonging to this group; the operator sets and activates the group management feature in the subscription information of the MTC equipment and stores the group management feature into a Home Subscriber Server (HSS). The HSS is an entity in charge of saving the identity information, authentication information and authorization information of a user or terminal equipment in the telecommunication network. depending on different circumstances, the HSS can be used to save the identity information of the user and the binding information of the user and the terminal equipment, or only the identity information of the user (specifically, the binding information of the user and the terminal equipment can be saved by a gateway), or directly save the identify information of the terminal equipment. The HSS is further in charge of a subscription database of users, user identity verification and authorization, and so on. The service platform can inquire the user or terminal information from the HSS.
When the MTC equipment is attached to a network, a Mobility Management Entity (MME) obtains the subscription information of the MTC equipment from the HSS and saves the information locally. The MME is an entity configured to manage the user terminal control signaling in the CN and is in charge of access control, including authentication control, identifier (for example, Globally Unique Temporary Identity (GUTI), Tracking Area Identity (TAI)) assignment, authentication of user identifier and equipment identifier, signaling plane encryption, consistency protection between eNBs, conversion of security parameters and Quality of Service (QoS) parameters between 2G/3G and Evolved Packet System (EPS), access permission control, decision on whether the requested resource can be obtained and reserved, legal monitoring, mobility management (tracking and recording of the current UE location), session management, related operations for EPS bearer, network element selection, etc.
After the MTC technology is introduced, there might exist a large number of MTC equipments; when the large number of MTC equipments all need to access the network to accept services, network congestion might occur due to overly large amount of signaling being initiated simultaneously, impacting the services for other terminals connected to the network.